Abstract
Schwannomas, also known as neurilemmomas, are benign, intracapsular peripheral nerve sheath tumors. They are the most common type of peripheral nerve sheath tumors and can be seen between the third and sixth decades of life, but are nevertheless rare. The goal of this report is to raise awareness in the medical community for this type of tumor.
A 21-year-old male patient presented with a mass in the right palm. He reported that he had noticed the mass two years before and that the numbness started three months before. We detected a mobile, soft, palpable mass, 3X1 cm in size, in zone three of the palm. Tinel’s test was positive. There was no history of neither neurofibromatosis nor any other hereditary diseases. USG showed a lobulated, encapsulated, highly vascularized and high resistant arterial flow solid mass with 11.5X28mm in size. Total excision was planned. Under general anesthesia the patient was placed in supine position. A 3 cm mid-palmar incision was made on the volar side of the right hand. Digital nerves and arteries were explored. The mass, which was found to be 30X15X10mm in size, emerged from the common digital nerve in zone three and was excised with microsurgical instruments via blunt dissection. The patient healed uneventfully. Histopathological examination of the mass revealed Vimentin S-100 positive schwannoma.
Schwannomas are rare, benign tumors. To the best of our knowledge, a similar large mass was reported in an infant and no case has been reported in adults. Hand surgeons should keep the schwannomas’ diagnosis in mind if upper extremity masses are isolated that are palpable and slow growing with positive Tinel’s sign. The presented study showed how big schwannomas can be in size and that the cure is achieved by total excision.

Key words: Schwannoma, neurilemmoma, hand, palmar, neurofibromatosis, S-100